Driving mechanism for locomotives.



S.G.THOMSQN. DRIVING MECHANISM FOR LOCOMOTIVES.

APPLICATION FILED MAY 18. 1915- Patented Apr. 11, 1916..

2 SHEETSSHEET S. G. THOMSON. DRIVING MECHANISM FOR LOCOMOTIVES.

APPLICATION FILED MAY 18. 1915.

Patented Apr. 11, 1916.

2 SHEETS-SHEET 2.

' INVENTOR 5 5M,

% 2 2i WWMO SAMUEL G. THOMSON,

0F READING, PENNSYLVANIA.

V DRIVING MECHANISM FOR LOCOMOTIVES.

To all'whomz'tmay concemf Be it known that I, SAMUEL G. THOMSON, a citizen of the United States, residing at- Reading, in the county of Berks and State of Pennsylvania, have invented a, new and useful Improvement in Driving Mechanism for Locomotives,'of which the following is a full,'clear, and exact description, reference being had to the accompanyin drawings, forming part of this spec cation, in which Figure 1 is a. view partly in side elevation, partly in vertical section, and somewhat diagrammatic, illustrating one form of locomotive driving mechanism embodying my invention. Figs. 2 and 3 are sections taken respectively on the lines II-II and III- III of Fig. 1. Fig. 4 is a side view of the cross-head, piston rod, piston, and piston rod extension. Figs. 5 and 6 are end views of Fig. 4, looking at opposite ends thereof, respectively. Figs. 7 and 8 and 9 are views similar respectively to Figs. 4, 5 and 6, but showing a modification of the cross-head- Fig. 10 is a view artly in side elevation, and partly in vertica section showing another form of cross-head and its guides. tion on the line II-'II f Fig. 10. Figs. 12, 13, 14, 15 and 16 are cross sectional views showing different forms of cross-heads and guides which may be employed.-

My invention has relation to driving mechanism for locomotives, and is designed to provide a driving mechanism in which the weight of the parts is materially reduced.

Modern development in locomotive design.

has created reciprocating parts in the driving mechanism of such size as to require excessive amounts of counterbalance in the wheels. This amount of added counterbalance, over and above the amount necessary to balance the revolving parts, results in damaged track to such an extent that reduction in catingparts is extremely desirable.

My invention is designed to provide a. construction in which this object is attained for modern .vhigh-speed locomotives and whereby such parts can be made much lighter than anything heretofore used, while at the same time they will have the proper strength.

The nature of my invention will be best understood by reference to the accompanying drawings in which I have shown a number of embodiments thereof, and which will Specification of Letters Patent.

Fig. 11 is a secthe weight of the recipro- Patented A r. 11, 191

Application filed May 18, 1915. Serial No. 28,829.

now *be described, it. being premised, however, that the invention is susceptible of various other embodiments within the scope of'the appended claims.

Referring first to that form of my invention shown in Figs. 1 to 6, inclusive, the

numeral 2 designates one of the locomotive cylinders, 3 the piston rod, 4 the piston, 5 the cross-head, 6 the main 'rod connected to the cross-head, 7 the cross-head guides,

8' the piston rod extension at the front of the cylinder, extension, and head 9. as consisting of a steel center portion 5 or 9 upon whichis cast facing portions 5" and 9 of some lighter metal, preferably aluminum. These facing portions may them selves provide the bearing surfaces for engagement with the cross-head guides; but preferably they are themselves provided wlth a facing 11 of suitable bearing material. The'steel centers of the cross heads are provided with suitable recesses 12, preferably of dovetailed form into which the aluminum facings'are cast, thus forming a secureljoint between the parts. of bearing metal are applied to the aluminum portions, the latter may also have suitable recesses, as indicated at 13, into which the bearing metal, such as lead or Babbitt metal, is cast. The'steel center may, however, be omitted in the cross-head 9, which may consist only of an aluminum center 10 a guide for the crosswith a facing of bearmg metal. The steel head. The aluminum portions act merely as the. guiding or spacing portions and greatly lighten the'weight of the cross-head as a whole. The cross-head guides 7 are shown in these figures as consisting of relatively thin plates bent at an angle to form V-shaped guides for the cross-head 5, the bearin portions of the latter being of correspon ing form. The cross-head guide 10 may be of similar construction, as shown in Fig. 3. This form of plate guides gives great resistance to both vertical and lateral thrusts, and at the same time the guides Each of the cross-heads. is shown- Where separate facings for the 9 a guiding cross-head on said afford stiffness in themselves on-account of I their shape. They are supported about midway of their length in the guide yoke1 5;" On account of the stifl' shape of the guides,

it is not-necessary to support them atthe ends.

The. feature of locating the guide yoke at an intermediate point in the length of the guides permits a much thinner and lighter plate to be used, since the unsupported span is only about one-half as long as when the guides are supported at their two end portions. Furthermore,'the thrust of the main rod against the cross-head guides 1s at a mam'mum at the midpoint; 101', in. other words, when the crank-pin of the drlving wheel is at the lower or upper quarter of its movement. The yoke support, therefore,

The shoes being detachable,'the guides can.

be readily lined up by the use of shims such as indicated at 7 in Figs. 12 and'13. At their opposite ends, the guides may be secured to the cylinder head by means of suitable clamps 7, having members 7 which fit the flange 2 of said head, and also within the V of the guide.

The cross-head guides must be spaced sufficiently far away from the center of the cross-head to allow proper angularity of the main rod 6. In the usual types of cross heads this has required the use of a large.

amount of metal in'the cross-head, adding greatly to the weight of the pa'rts where strength is not required. By the angular design of cross-heads shown, the cross-head bearing surfaces are brought as closely to the center of the cross-head as possible, while allowing suflicient clearance for set screws, keys, etc., in the main rod and which are arranged adjacent to the vertical longitudinal center line of the rod. This construction of the guides also largely reduces the weight of the parts.

prefer to make the piston rod extension 8 in the form ofa light tubing of substantially the same diameter as the diameter of.

the piston rod and having a bushing 16 forced into its rear end. This bushing is internally threaded and is screwed to'the end of the piston rod. When tightened in this position, the tubing is then welded, king a, very substantial connection. The connection may, however, be made in any other suitable way. It may of course be attached to an extension of the piston head instead of to the piston rod. The novel feature consists in theme of a light piece of tubing as the rod extension, rather than making it of the same forging as the piston rod and relying on drilling holes through its center to afford lightness. Tubing of large diameter can be'used without involving much metal, and great stifiness can thus be obtained with a comparatively small weight.

The cross-head 9 is preferably mounted the cross-head the central V-portions 36 of complementary so as to be turned on the end of'the piston rod extension and reversed edge for'edge so that as itslower portion becomes worn, it

portions which seat the side rings, so that when the groove is filled with the rin s a greater seal is provided against steam b owing through under the rings or between the packing rings and the cylinderf The two slde rings may be doweled to the piston head, as indicated at 4, in such positions that their ends will be at opposite sides of the piston. The middle ring may then be allowed to float between the twoside rings;

This arrangement will never permit the endsof all three rings getting together and thereby giving an opportunity for the steam to blow through.

Figs. 7, 8 and 9 illustrate a modification in which the crossahead 19 has only one bearing portion'20, this preferably being of aluminum cast to a steel center. Fig. 10 shows another form of cross-head the top bearing portion 21 is made longer than" the bottom bearing portion 22. This figure, together with Fig. 11 shows more in detail the manner-in which the cross-head guides 7 are supported in the yoke 15. Fig. 12 shows a form of cross-head and guides in which the inverted V-form similar to that first described, while the lower guide 24: is of flat plate form, and the cross-head has the guiding flanges 25 which embrace the edges of the lower guide. In Fig. 13 the construction of Fig. 14 is reversed, the V-shaped guide 26 being at the bottom and the flat guide 27 at the top. Fig. 14 shows aform in which the top guide 28 is curved to the arc of a circle, while the lower guide 29 is of angular form. Fig. 15 shows a modification in whichonly the top guide 30 is employed, this having a T-shaped guide slot 31, and the cross-head having a corresponding portion 32 sliding therein. Fig. 16 shows a modification in which the crosshead has a T-head 33 sliding in a way 34 of corresponding shape in the top guide 35, and the guide-way having form. These various forms are illustrative only as showing difi'erent possible embodiments of my invention.

While I have spoken herein of the use of in which the upper guide 23 is of aluminum in the cross-heads, course, use any of the various suitable alloys of aluminum, such as those in which small portions of tin, copper and nickel are added, since pure aluminum is difiicult to use where strength is required or where machining or threaded work is to depended tion makes practical use of such alloys in a service which is unusually severe; and the benefits afforded by the reductions in weight are very marked. By the term aluminum as used herein and in the appended claims, I intend therefore to include various alloys in which aluminum forms the main element.

I claim: I 0

1. A driving mechanism for a locomotive,

comprising a cross-head and guide, said cross-head having a steel portion to provide connections for the main rod and the piston 7 rod, and said steel portion having an aluminum portion fastened to it and interposed between it and said guide.-

2. A driving mechanism for-a locomotive, comprising a. cross-head and guide, said cross-head having a steel portion and an aluminum portion, said aluminum portion to. engage said guide.

having a facing 3. A driving mechanism for a locomotive,

, comprising a cross-head and guide, said cross-head having a central steel portion to. a

provide connections for a main rod and piston rod, and said steel portion having an aluminum cage portion attached thereto.

4. A driving mechanism for a locomotive,

- comprising a cross-head and guide, said cross-head havin an aluminum member with recessed or ove-tailed grooves to rec61 1; bearing metal to contact. with said gui e. 4

5. A driving mechanism for a locomotive, having a cross-head witha steel central portion to provide connections for a main rod and a having a plurality of-projections, and an aluminum portion cast around said projections.

6. A driving having a crosshead with a steel central portion to rovide connections for a main rod and a piston rod, said steel central portion providing re tions, said aluminum portion to hold a faccesses or dove-tailed grooves ing of bearing metal for said cross-head.

p A locomotive prising a cylinder, a piston therein, apiston rod having. a crosshead, and a concave guide, said guide forming concaved bearing faces for the crosshead and fastened I may, of

be greatly upon. I believe that my invenpiston rod, said steel central portion mechanism for a locomotive,

driving mechanism, comguideat one end to the locomotive, together with a guide yoke to which said guide is fastened adjacent to its middle portion.

8; A locomotive driving mechanism, comprising a cylinder, a piston therein, a piston rod having a crosshead, and'a guide for said crosshead, said guide uiding surfaces for similar angular 'bearmg faces on the crosshead, said guidebeing fastened at one end also fastened adjacent to its mid-length by means of a guide yoke. 9 A locomotive drivingmeclianism, comprising a cylinder, apiston therein, a piston rod having a cross-head, and oppositely arranged guides for said cross-head consistwhich said plate members are fastened adjacent to their middle portions.

A locomotive driving mechanism, com,- prising a cylinder, a piston therein, a piston rod, a cross-head connected to the piston rod, a main driving rod connected to the cross-head, and upper and lower guides for said head, said guides having concaved bearing faces, and being unsupported near their rear ends, the concave form ofsaid guides and I the absence of supporting means at their rear portions permitting a maximum angularity of the driving rod,

with a minimum separation of the guides.

11. A locomotive driving mechanism, comprising a cylinder, a piston therein, a piston-rod'having a crosshead, and oppositely arranged guides for said head, said guides being formed give concaved bearing surfaces forthe head, and a supporting yoke for the guide having rigid shoes provided with seats for the guides and conforming approximately thereto.

12. A locomotive prising a cylinder, a piston therein, a piston-rod having a cros head, and oppositely arranged guides for said head, said guides being formed of thin plate metal shaped to give concaved bearing ,surfaces for the head, anda supporting yoke for ides and conforming approximately thereto, said shoes being detachable. to facilitate lining up of the guides.

In testimony whereof, I havehereunto set my hand. 7 I

4 SAMUEL G. TiioMsoN...

Witnesses: HARRY EGOLF,

" J..J WEIGHTMAN.

forming. V-shaped of ,thin plate metal shaped to the guide havingrigid shoes provided with seats for the to the locomotive and driving mechanism, com- 7 

